In this paper, we present a wavelet transform based coding approach by employing modiied rate-distortion function and hybrid optimum classiication. In the proposed approach, each upper band subimage from wavelet decomposition is optimally classiied to achieve the minimum quantization error, according to an eecient prediction model and a modiied rate-distortion function. The performance of the a...

The optimum noncoherent multiuser detector is obtained for generalized diversity symbol-synchronous communication systems that employ nonorthogonal multipulse modulation. A unified approach is adopted to simultaneously address various forms of diversity such as time, frequency, multipath, and/or receiver–antenna diversity. Upper and lower bounds on the average bit-error probability of the optim...

Multitone modulations are today frequently used modulation techniques that enable optimum utilization of the frequency band provided on non-ideal transmission carrier channel (Bingham, 2000). These modulations are used with especially in data transmission systems in access networks of telephone exchanges in ADSL (asymmetric Digital Subscriber Lines) and VDSL (Very high-speed Digital Subscriber ...

In this paper, the optimum transmits power for an optical code division multiple access (OCDMA) is analyzed at different data rates and transmission distance. We used Enhance Double Weight (EDW) codes as a signature address in designing the system because this code can accommodate more number of simultaneous users under considerable standard Bit-Error-Rate (e.g. ≤ 10). The induced EDW codes for...

The usage of Orthogonal Frequency Division Multiplexing (OFDM) allows to adapt the available time-frequency grid to the current channel conditions. To exploit the offered degrees of freedom many bit and power loading algorithms were introduced. However, they do not include channel coding in the optimization. Similar to conventional multicarrier schemes in such link adaptation scenarios the peak...

This paper will focus on improving the performance of orthogonal frequency division multiplexing (OFDM) in Rayleigh fading environments. The proposed technique will use a previously published method that has been shown to improve OFDM performance in independent fading, based on ordered sub-carrier selection. Then, a simple non-iterative method for finding the optimal bit-loading allocation was ...

The optimum receive antenna selection combining rule that minimizes the bit error probability is presented. It is derived from a general relationship between the bit error probability and the log-likelihood ratio (LLR), and selects the receive antenna providing the largest LLR magnitude. The optimum selection combining rule is applied to single transmit (Tx) antenna and space-time block code (S...

In recent history there has been an enormous development in the subject area of Power Line Communications (PLC), since it has become possible due to advanced digital communications and digital signal processing techniques to use power lines for data transmission. PLC allows the use of the dynamic and far-reaching power cables to support high speed communication capabilities. Discrete Multi-tone...

This paper presents an adaptive cross-layer resource allocation problem with the fairness in multi-user OFDMMISO communication systems, and provides two solutions with Hopfield Neural Network (HNN) and Genetic Algorithm (GA) for the problem. We utilized HNN’s characteristics such as parallel processing, fast convergence speed and easy convergence to the optimum, to solve this problem under the ...

In this paper, a scalable multimedia system with unequal error probabilities (UEP) is considered. A combination of adaptive modulation and hierarchical (embedded) constellations is implemented to realize three different levels of data priorities. The highest priority data bits spread over all available subcarriers with a relatively low modulation order. The next data levels are embedded on top ...